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Whole apples have not been previously implicated in outbreaks of foodborne bacterial illness. We investigated a nationwide listeriosis outbreak associated with caramel apples. We defined an outbreak-associated case as an infection with one or both of two outbreak strains of Listeria monocytogenes highly related by whole-genome multilocus sequence typing (wgMLST) from 1 October 2014 to 1 February 2015. Single-interviewer open-ended interviews identified the source. Outbreak-associated cases were compared with non-outbreak-associated cases and traceback and environmental investigations were performed. We identified 35 outbreak-associated cases in 12 states; 34 (97%) were hospitalized and seven (20%) died. Outbreak-associated ill persons were more likely to have eaten commercially produced, prepackaged caramel apples (odds ratio 326·7, 95% confidence interval 32·2–3314). Environmental samples from the grower's packing facility and distribution-chain whole apples yielded isolates highly related to outbreak isolates by wgMLST. This outbreak highlights the importance of minimizing produce contamination with L. monocytogenes. Investigators should perform single-interviewer open-ended interviews when a food is not readily identified.

EUVE J2056-17.1 is one of the brightest sources in the First EUVE Source Catalog with 0.24 counts s−1 in the Deep Survey Lexan/B band. We present optical and EUV results that show this source is one of the most active late-type dwarfs. EUVE observed a large flare with energy in excess of 1035 ergs in its Lexan/B band. The quiescent optical spectrum of the source reveals strong hydrogen Balmer and Ca II H and K emission. A strong Li I 6707 Å line is also present in the spectrum. We have estimated a Li abundance of log N(Li) = 2.5±0.4. The high Li abundance and the high flare activity favors an interpretation where the enhanced Li is sustained by spallation reactions.

The experiment investigated the effect of maternal dietary supplementation of seaweed-derived polysaccharides (SDP) (–SDP v. +SDP, n 20) from day 83 of gestation until weaning (day 28) on selected sow faeces and piglet digesta microbiota populations, piglet small-intestinal morphology, and intestinal nutrient transporter and inflammatory cytokine gene expression at birth, 48 h after birth and weaning. The effect of maternal dietary treatment on the piglet gene expression profile of inflammatory cytokines in the colon following a lipopolysaccharide (LPS) challenge was also investigated. Dietary SDP reduced sow faecal Enterobacteriaceae gene numbers at parturition. Small-intestinal morphology, nutrient transporter and cytokine gene expression in newborn piglets did not differ between maternal dietary treatments (P > 0·10). At 48 h after birth, sodium–glucose-linked transporter 1 gene expression was down-regulated in the ileum of piglets suckling the SDP-supplemented sows compared with those suckling the basal sows (P = 0·050). There was a SDP × LPS challenge interaction on IL-1 and IL-6 gene expression in the colon of piglets (P < 0·05). The gene expression of IL-1 and IL-6 was down-regulated in the LPS-challenged colon of piglets suckling the SDP sows compared with those suckling the basal sows (P < 0·05). However, there was no difference in IL-1 and IL-6 gene expression in the unchallenged colon between treatment groups. At weaning, piglets suckling the SDP-supplemented sows had increased villus height in the jejunum and ileum compared with those suckling the basal-fed sows (P < 0·05). In conclusion, maternal dietary SDP supplementation enhanced the immune response of suckling piglets and improved gut morphology, making them more immune competent to deal with post-weaning adversities.

In most mental illnesses, onset occurs before the age of 25 and the earliest stages are critical. The youth bear a large share of the burden of disease associated with mental illnesses. Yet, Canadian youths with mental health difficulties face delayed detection; long waiting lists; inaccessible, unengaging services; abrupt transitions between services; and, especially in remoter regions, even a complete lack of services. Responding to this crisis, the Canadian Institutes of Health Research announced a 5-year grant that was awarded to ACCESS, a pan-Canadian network of youths, families, clinicians, researchers, policymakers, community organisations and Indigenous communities. Using strategies developed collaboratively by all stakeholders, ACCESS will execute a youth mental healthcare transformation via early detection, rapid access and appropriate, high-quality care. The project includes an innovative, mixed-methods service research component. Similar in many respects to other national youth mental health initiatives, ACCESS also exhibits important differences of scale, scope and approach.

In the present study, a 2 × 2 factorial arrangement was conducted to investigate the effect of maternal supplementation with seaweed extracts ( − SWE v. +SWE, n 20) from day 83 of gestation until weaning (day 28) on post-weaning (PW) growth performance, faecal score, faecal enterotoxigenic Escherichia coli (ETEC) toxin quantification, intestinal histology and cytokine mRNA of unchallenged and ETEC-challenged pigs. Pigs were ETEC challenged on day 9 PW. There was a maternal treatment × challenge (SWE × ETEC) interaction effect on growth performance and faecal score (P< 0·05). Pigs from SWE-supplemented sows and ETEC-challenged (SE) had higher average daily gain (ADG) during 0–13 d PW and reduced faecal score during 0–72 h post-challenge than those from basal-fed sows and ETEC-challenged (BE) (P< 0·05). However, there was no difference between unchallenged pigs from the SWE-supplemented sows (SC) and basal-fed sows (BC) (P>0·10). Pigs from the SWE-supplemented sows had reduced heat-labile enterotoxin gene copy numbers than those from the basal-fed sows (P< 0·05). Maternal SWE supplementation increased the villus height in the ileum of pigs (P< 0·05). There was a SWE × ETEC interaction effect (P< 0·05) on IL-6 mRNA and a SWE × gastrointestinal (GI) region interaction effect (P< 0·05) on transforming growth factor-β1 (TGF-β1) and TNF-α mRNA. IL-6 mRNA was down-regulated in SC pigs than BC pigs (P< 0·05). However, there was no difference in IL-6 mRNA between SE and BE pigs. The mRNA of TGF-β1 and TNF-α was down-regulated in the colon of pigs from the SWE-supplemented sows compared with those from the basal-fed sows (P< 0·05). However, there was no difference in TGF-β1 and TNF-α mRNA in the ileum between the pigs from the SWE-supplemented sows and basal-fed sows. In conclusion, maternal SWE supplementation improves ADG and the aspects of GI health of weaned pigs following an ETEC challenge.

In the present study, two experiments were conducted to (1) evaluate the effect of laminarin and/or fucoidan on ileal morphology, nutrient transporter gene expression and coefficient of total tract apparent digestibility (CTTAD) of nutrients and (2) determine whether laminarin inclusion could be used as an alternative to ZnO supplementation in weaned pig diets. Expt 1 was designed as a 2 × 2 factorial arrangement, comprising four dietary treatments (n 7 replicates, weaning age 24 d, live weight 6·9 kg). The dietary treatments were as follows: (1) basal diet; (2) basal diet+300 ppm laminarin; (3) basal diet+240 ppm fucoidan; (4) basal diet+300 ppm laminarin and 240 ppm fucoidan. There was an interaction between laminarin and fucoidan on the CTTAD of gross energy (GE) (P< 0·05) and the expression of sodium–glucose-linked transporter 1 (SGLT1/SLC5A1) and GLUT1/SLC2A1 and GLUT2/SLC2A2 (P< 0·05) in the ileum. The laminarin diet increased the CTTAD of GE and increased the expression of SGLT1, GLUT1 and GLUT2 compared with the basal diet. However, there was no effect of laminarin supplementation on these variables when combined with fucoidan. Expt 2 was designed as a complete randomised design (n 8 replicates/treatment, weaning age 24 d, live weight 7·0 kg), and the treatments were (1) basal diet, (2) basal diet and laminarin (300 ppm), and (3) basal diet and ZnO (3100 ppm, 0–14 d, and 2600 ppm, 15–32 d post-weaning). The laminarin diet increased average daily gain and gain:feed ratio compared with the basal diet during days 0–32 post-weaning (P< 0·01) and had an effect similar to the ZnO diet. These results demonstrate that laminarin provides a dietary means to improve gut health and growth performance post-weaning.

Alkyl-terminated SixG1-x nanocrystals are prepared at room temperature by co-reduction of Si and Ge precursors by hydride reducing agents within inverse micelles. Compositional control of the alloy silicon-germanium NCs (ca. 3.6 nm) is achieved by varying the relative amounts of each precursor used in the synthesis. Transmission electron microscopy imaging confirmed that the NCs are highly crystalline with a narrow size distribution; optical spectroscopy shows strong quantum confinement effects, with moderate absorption in the UV spectral range, and a strong blue emission with a marked dependency on excitation wavelength.

A 2 × 2 factorial experiment was conducted to investigate the interactions between laminarin (LAM; 0 and 300 parts per million (ppm)) and fucoidan (FUC; 0 and 240 ppm) levels on intestinal morphology, selected microbiota and inflammatory cytokine gene expression in the weaned pig. There was an interaction between LAM and FUC supplementation on the Enterobacteriaceae population (P< 0·05) and the abundance of attaching and effacing Escherichia coli (AEEC) strains (P< 0·05) in the colon. Pigs offered the FUC diet had a reduced Enterobacteriaceae population compared with pigs offered the basal diet. However, the effect of FUC on the Enterobacteriaceae population was not observed when combined with LAM. Pigs offered the LAM diet had reduced abundance of AEEC strains compared with pigs offered the basal diet. However, there was no effect of LAM on the abundance of AEEC strains when combined with FUC. There was an interaction between LAM and FUC supplementation on villous height (P< 0·01) and the villous height:crypt depth ratio (P< 0·01) in the duodenum. Pigs offered the LAM or FUC diet had an increased villous height and villous height:crypt depth ratio compared with pigs offered the basal diet. However, there was no effect of the LAM and FUC combination diet on intestinal morphology. Pigs offered the LAM-supplemented diets had a lower IL-6 (P< 0·05), IL-17A (P< 0·01) and IL-1β (P< 0·01) mRNA expression in the colon compared with pigs offered the diets without LAM. In conclusion, supplementation with either LAM or FUC alone modified intestinal morphology and selected intestinal microbiota, but these effects were lost when offered in combination.

Predominantly 6H <0001> SiC single crystals have been implanted with nitrogen and aluminum at 300°K. The effects of implantation and post-implantation annealing at 573–1173°K have been characterized by Rutherford backscattering/channeling, microhardness measurements and transmission electron microscopy. Even at 1173°K, defect annealing was inhibited in amorphized regions. Progressive damage recovery as the anneal temperature was increased was otherwise generally observed. Fluences predicted by the critical damage energy of 2 × 1021 keV/cm3 did not quite produce amorphization to x = 0. In the as-implanted specimens, decreasing hardness was observed with increasing fluence. Significant surface softening (∼ 33% hardness reduction) was achieved at the highest aluminum fluence (5 × 1015 Al/cm2) and was stable at temperatures < 893°K.

The effects of chemical etching, mechanical thinning, and ion milling on the low temperature photoluminescence spectra of MBE grown (001) CdTe films are reported. Line defects observed by TEM are correlated with photoluminescence. It is shown that X-ray D.C.R.C, measurements in these films are weighted averages over the whole thickness of the films and therefore weakly reflect the structural perfection of the samples near the surface as deduced by photoluminescence.

X-ray diffraction techniques have proved invaluable in the characterization of infrared materials, particularly those prepared by thin film deposition techniques such as molecular beam epitaxy, MBE. The techniques are sufficiently sensitive and rapid to provide the information feedback required for efficient optimization of the growth process. They are nondestructive and permit the correlation with results on the same sample obtained by other characterization techniques such as those being described at this Symposium. Depending on the development status of the growth technology, the information to be acquired includes presence of twinning, quality, and type of epitaxial orientation, strains, and compositional variations. A critical issue in the application of these materials in detector arrays is the question of uniformity control, both laterally and in depth. The techniques to be described include not only modern x-ray topographic and multiple crystal diffractometric techniques but particularly for the early stages of growth process development, classical photographic ones such as the oscillation and Weissenberg methods. Examples of these various aspects are presented with emphasis placed on the characterization involved in MBE growth of HgCdTe films.

Reactive magnetron sputtering (RMS) is a versatile technique for the production of alloy thin film coatings such as hydrides, nitrides, oxides, etc. RMS provides control over (i) film stoichiometry, via the partial pressure of “reactive” gas (H2, N2, etc.) injected, and (ii) film microstructure, via the bombardment of the growing surface by fast neutral or accelerated ionic species. However, few details are known about the fluxes reaching the film surface, and their reactions with it.

This paper reports comprehensive measurements for the RMS growth of hydrogenated amorphous silicon (a-Si:H). The analysis techniques are in situ double modulation mass spectroscopy, plasma probes, isotope replacement experiments, and Monte-Carlo simulations of sputtered particle transport. We determine (i) the composition, energy and angular distributions of the incident flux, (ii) the H coverage of the growing surface, and (iii) the release of H2 from the growing film. For conditions which produce electronic quality a-Si:H, the total H flux arriving at the substrate varies between 0.5–2 times the depositing Si flux; about half of the H flux reflects. The growth surface has excess H varying between 0.5–2 × 1015/cm2, and this surface H coverage is linearly related to the bulk H incorporation. We also find evidence that film density varies with the energy of the arriving sputtered Si atoms.

Implantation of nitrogen into steels is known to affect surface sensitive mechanical properties. Tensile properties of thin foils implanted with either nitrogen or helium at 300 K have been measured. Fluences greater than 1 × 1016 ions/cm2 raise the yield stress and fracture stress and reduce the plastic strain to failure. Both nitrogen and helium give comparable stress-strain responses for equal average concentrations of implanted ions. The mechanical response is discussed in terms of plastic flow of laminated structures and hardening mechanisms. Initial results of atom probe field ion microscopy examinations of nitrogen implanted Fe-15 wt.% Cr-12 wt.% Ni alloy are described.

Experiments have been performed to assess the feasibility of using ionbeam sputter deposition for the growth of CdTe, HgTe and HgCdTe films. Some simple cryogenically cooled dual-target configurations have been employed in an investigation of epitaxial growth on CdTe substrates. Good-quality epitaxy was achieved for CdTe at temperatures down to 140°C, and for HgTe and HgCdTe at temperatures extending to below 50° C.Based upon compositional and phase analyses, and upon IR absorption measurements, we conclude that, using an excess Hg flux, stoichiometric transfer of the HgCdTe target composition to the substrate is approximately obtained. However, some departure from stoichiometry is produced at higher substrate temperatures (> 150”C) due to thermal re-evaporation of Hg, and under high sputtered Hg fluxes due to selective re-sputtering of HgTe. The good structural quality and excellent compositional uniformity of the films indicate that ion-beam sputter deposition may be suitable for low-temperature processing of IR detector structures.

Double modulated beam mass spectrometry was used to obtain the first measurements of the identity, relative flux, and energy of film precursors in reactive dc magnetron sputtering. In these experiments, a 2″ diameter silicon target was sputtered in an argon plus deuterium plasma at an argon pressure of 1.5 mTorr. This system produces high quality a-Si:D. Energetic neutral Si and SiD were observed, while energetic neutral SiD2 and SiD3 were absent. The arrival rate of D in the form of SiD increased and then saturated at 19 percent of the total flux as the deuterium pressure was varied from 0 to 5 mTorr. The sputtered Si energy agreed qualitatively with the standard Thompson theory. Energetic ions located at mass 2 and 4 were measured with energies much greater than the sputtered Si. Thermal silane was also detected, raising the possibility that thermal silane radicals in addition to energetic Si and SiD contribute to film growth.

The interdiffusion and crystallization reactions between amorphous Ni-Nb alloy films and Si substrates and several overlayer metals have been monitored by x-ray diffraction and high resolution Rutherford backscattering spectroscopy. Free standing amorphous thin films of Ni-Nb alloys crystallize in one hour at temperatures between 600–625 °C and show little dependence of the crystallization temperature, Tx, on composition over the range from 30–80 at.% Ni. However, in films that are sputter deposited onto Si substrates Tx tends to increase with increasing Nb composition. Ni60Nb40 samples without overlayers crystallize at 650–700 °C. Enhancement of the thermal stability to 700–750 °C is achieved with a Nb overlayer. In contrast, a Ni overlayer can reduce Tx to 450 °C. At the film/substrate interface silicide formation reactions with Ni from the film contribute to a destabilization of the amorphous alloy. The modification of Tx with Ni, Nb, and other overlayers appears to be related to changes in the reaction kinetics associated with penetration of the overlayer into the film.

High quality a-Si:H films are deposited by d.c. magnetron reactive sputtering of a Si target in an (Ar + H2) plasma. This paper reports the first comprehensive understanding of the growth process. The incident flux, surface H coverage, H2 release, and bulk H incorporation are determined using four in situ, real time techniques: double modulation mass spectroscopy, isotope replacement experiments, reflection absorption infra-red spectroscopy, and spectroscopic ellipsometry. In addition, the sputtered particle transport is simulated using Monte-Carlo techniques. For conditions which produce electronic quality a-Si:H, the total H flux arriving at the surface varies between 0.5 – 2 times the depositing Si flux; approximately half of this flux appears to reflect from the surface without interaction. The growth surface has excess H varying between 0.5 – 2 × 1015/cm2, and this surface H coverage is uniquely related to the bulk H incorporation.

The formation and annealing of buried damage layers in hydrogen implanted N-type float zone <111> silicon has been studied by Rutherford Backscattering/ion channeling and cross-section transmission electron microscopy. Implantation with 50 keV or 75 keV H+ ions was conducted at temperatures of 95K, 300K and 800K at fluences of 2×1017 H+/cm2, 8×1017 H+/cm2 and 1×1018 H+/cm2. Post implantation annealing was conducted at temperatures up to 800K. The results show a temperature dependent transition from a highly hydrogen doped amorphous zone bounded by strongly diffracting (TEM) 2–5 nm diameter defects for implantation at 95K to a crystalline microstructure containing small dislocation loops and ∼40% of the implanted hydrogen for implantation at 300K. Defect production and annealing and hydrogen trapping in the damage zone are shown to depend on the relative implantation and post implantation annealing temperatures.

Electrically active defects in both 4H and 6H polytypes of SiC have been observed through the use of deep level transient spectroscopy (DLTS). Schottky contacts were grown by vapor phase epitaxy (VPE) with doping concentrations, the epitaxial layer having a doping concentration in the range of 1014 cm−3 to 1017cm−3. Numerous levels have been found in the as-grown n-type 6H-SiC samples and secondary ion mass spectrometry (SIMS) and MeV electron irradiation have been employed to corrrelate the defect levels to impurities or structural defects. In contrast, only a single level is observed in the as-grown 4H-SiC samples.